The present invention relates to a die bonder and a bonding method, and more particularly, to a die bonder and a bonding method which allow processing of a wafer with a plurality of grades without removing the wafer.
A process of assembling a package by mounting a die (semiconductor chip) (hereinafter simply referred to as a die) onto the substrate such as a wiring substrate and a lead frame includes a step of separating a die from a semiconductor wafer (hereinafter simply referred to as a wafer), and a step of bonding the separated die onto the substrate.
The dies to be picked up on the wafer are classified into a plurality of grades in accordance with electric properties, which are stored in a memory of a control unit. When mounting the dies with a plurality of grades onto the substrate, the die bonder corresponding to the grade has to be selected from the different die bonders and exchanged, which may take time, and reduce productivity. If the wafer that has been once picked up is removed from the die bonder, the remaining dies are brought into contact with one another because of loosened tensile force of the sheet, which may cause the risk of breaking and reduced yield.
The technology for solution of the above-described problem is disclosed in JP-A No. 07-193093, which allows the bonding head to bond the dies with a plurality of grades for each of a plurality of lanes that convey the lead frame.